<div>

<!-- Width zero with content -->
<div style="width: 0;">GHI</div>
<div style="width: 0; word-wrap: break-word;">DEF</div>

<!-- Width zero with breakable content -->
<div style="width: 0;">PQR STU</div>
<div style="width: 0; word-wrap: break-word;">VWX 123</div>

<!-- Width zero with no content -->
<div style="width: 0;"></div>
<div style="width: 0; word-wrap: break-word;"></div>

<!-- Negative content width with content -->
<div style="box-sizing: border-box; width: 5px; padding: 0 5px;">JKL</div>
<div style="box-sizing: border-box; width: 5px; padding: 0 5px; word-wrap: break-word;">MNO</div>

<!-- Negative content width without content -->
<div style="box-sizing: border-box; width: 5px; padding: 0 5px;"></div>
<div style="box-sizing: border-box; width: 5px; padding: 0 5px; word-wrap: break-word;"></div>

<!-- Zero width table cell as result of layout -->
<table style="width: 3px;table-layout: fixed;">
<tr>
 <td colspan="2"></td>
 <td style="word-wrap: break-word;">ABC</td>
</tr>
</table>

</div>
